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authorCyrill Gorcunov <gorcunov@gmail.com>2009-01-28 23:21:25 +0300
committerIngo Molnar <mingo@elte.hu>2009-01-29 14:37:01 +0100
commit0a1e8869f453ceda121a1ff8d6c4380832377be7 (patch)
treee895cb1e5caa7ca2b1542f8de1e056004ea4f512 /arch/x86/kernel/trampoline_64.S
parent2d4d57db692ea790e185656516e6ebe8791f1788 (diff)
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x86: trampoline_64.S - use predefined constants with simplification
Impact: cleanup We may use macros from processor-flags.h instead of hardcoding bits. Actually it's not direct mapping of old instructions with new ones -- BTS does change CF flag while MOV does not. But i didn't find any dependency on CF in this code. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Alexander van Heukelum <heukelum@fastmail.fm> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/trampoline_64.S')
-rw-r--r--arch/x86/kernel/trampoline_64.S19
1 files changed, 9 insertions, 10 deletions
diff --git a/arch/x86/kernel/trampoline_64.S b/arch/x86/kernel/trampoline_64.S
index 894293c598db..95a012a4664e 100644
--- a/arch/x86/kernel/trampoline_64.S
+++ b/arch/x86/kernel/trampoline_64.S
@@ -29,6 +29,7 @@
#include <asm/page.h>
#include <asm/msr.h>
#include <asm/segment.h>
+#include <asm/processor-flags.h>
.section .rodata, "a", @progbits
@@ -37,7 +38,7 @@
ENTRY(trampoline_data)
r_base = .
cli # We should be safe anyway
- wbinvd
+ wbinvd
mov %cs, %ax # Code and data in the same place
mov %ax, %ds
mov %ax, %es
@@ -73,9 +74,8 @@ r_base = .
lidtl tidt - r_base # load idt with 0, 0
lgdtl tgdt - r_base # load gdt with whatever is appropriate
- xor %ax, %ax
- inc %ax # protected mode (PE) bit
- lmsw %ax # into protected mode
+ mov $X86_CR0_PE, %ax # protected mode (PE) bit
+ lmsw %ax # into protected mode
# flush prefetch and jump to startup_32
ljmpl *(startup_32_vector - r_base)
@@ -86,9 +86,8 @@ startup_32:
movl $__KERNEL_DS, %eax # Initialize the %ds segment register
movl %eax, %ds
- xorl %eax, %eax
- btsl $5, %eax # Enable PAE mode
- movl %eax, %cr4
+ movl $X86_CR4_PAE, %eax
+ movl %eax, %cr4 # Enable PAE mode
# Setup trampoline 4 level pagetables
leal (trampoline_level4_pgt - r_base)(%esi), %eax
@@ -99,9 +98,9 @@ startup_32:
xorl %edx, %edx
wrmsr
- xorl %eax, %eax
- btsl $31, %eax # Enable paging and in turn activate Long Mode
- btsl $0, %eax # Enable protected mode
+ # Enable paging and in turn activate Long Mode
+ # Enable protected mode
+ movl $(X86_CR0_PG | X86_CR0_PE), %eax
movl %eax, %cr0
/*